RESUMO
Lactate accumulates to a significant amount in glioblastomas (GBMs), the most common primary malignant brain tumor with an unfavorable prognosis. However, it remains unclear whether lactate is metabolized by GBMs. Here, we demonstrated that lactate rescued patient-derived xenograft (PDX) GBM cells from nutrient-deprivation-mediated cell death. Transcriptome analysis, ATAC-seq, and ChIP-seq showed that lactate entertained a signature of oxidative energy metabolism. LC/MS analysis demonstrated that U-13C-lactate elicited substantial labeling of TCA-cycle metabolites, acetyl-CoA, and histone protein acetyl-residues in GBM cells. Lactate enhanced chromatin accessibility and histone acetylation in a manner dependent on oxidative energy metabolism and the ATP-citrate lyase (ACLY). Utilizing orthotopic PDX models of GBM, a combined tracer experiment unraveled that lactate carbons were substantially labeling the TCA-cycle metabolites. Finally, pharmacological blockage of oxidative energy metabolism extended overall survival in two orthotopic PDX models in mice. These results establish lactate metabolism as a novel druggable pathway for GBM.
Assuntos
Glioblastoma , Acetilação , Animais , Linhagem Celular Tumoral , Epigênese Genética , Glioblastoma/genética , Glioblastoma/patologia , Histonas/metabolismo , Humanos , Ácido Láctico/metabolismo , CamundongosRESUMO
Glioma growth is driven by signaling that ultimately regulates protein synthesis. Gliomas are also complex at the cellular level and involve multiple cell types, including transformed and reactive cells in the brain tumor microenvironment. The distinct functions of the various cell types likely lead to different requirements and regulatory paradigms for protein synthesis. Proneural gliomas can arise from transformation of glial progenitors that are driven to proliferate via mitogenic signaling that affects translation. To investigate translational regulation in this system, we developed a RiboTag glioma mouse model that enables cell-type-specific, genome-wide ribosome profiling of tumor tissue. Infecting glial progenitors with Cre-recombinant retrovirus simultaneously activates expression of tagged ribosomes and delivers a tumor-initiating mutation. Remarkably, we find that although genes specific to transformed cells are highly translated, their translation efficiencies are low compared with normal brain. Ribosome positioning reveals sequence-dependent regulation of ribosomal activity in 5'-leaders upstream of annotated start codons, leading to differential translation in glioma compared with normal brain. Additionally, although transformed cells express a proneural signature, untransformed tumor-associated cells, including reactive astrocytes and microglia, express a mesenchymal signature. Finally, we observe the same phenomena in human disease by combining ribosome profiling of human proneural tumor and non-neoplastic brain tissue with computational deconvolution to assess cell-type-specific translational regulation.
Assuntos
Neoplasias Encefálicas/metabolismo , Transformação Celular Neoplásica/metabolismo , Glioma/metabolismo , Ribossomos/metabolismo , Animais , Encéfalo/metabolismo , Encéfalo/patologia , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Transformação Celular Neoplásica/genética , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Glioma/genética , Glioma/patologia , Humanos , Camundongos , Ribossomos/genéticaRESUMO
Mechanisms that regulate oligodendrocyte (OL) precursor migration and differentiation are important in normal development and in demyelinating/remyelinating conditions. We previously found that the tetraspanin CD82 is far more highly expressed in O4(+) OL precursors of the adult rat brain than those of the neonatal brain. CD82 has been physically linked to cMet, the hepatocyte growth factor (HGF) receptor, in tumor cells, and this interaction decreases downstream signaling. We show here that CD82 inhibits the HGF activation of cMet in neonatal and adult rat OL precursors. CD82 expression is sufficient to allow precursor differentiation into mature OLs even in the presence of HGF. In contrast, CD82 downregulation in adult O4(+)/CD82(+) cells inhibits their differentiation, decreases their accumulation of myelin proteins, and causes a reversion to less mature stages. CD82 expression in neonatal O4(+)/CD82(-) cells also blocks Rac1 activation, suggesting a possible regulatory effect on cytoskeletal organization and mobility. Thus, CD82 is a negative regulator of HGF/cMet during OL development and overcomes HGF inhibitory regulation of OL precursor maturation.
Assuntos
Diferenciação Celular/efeitos dos fármacos , Fator de Crescimento de Hepatócito/farmacologia , Proteína Kangai-1/farmacologia , Oligodendroglia/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-met/metabolismo , Células-Tronco/efeitos dos fármacos , Adulto , Animais , Animais Recém-Nascidos , Encéfalo/citologia , Encéfalo/crescimento & desenvolvimento , Encéfalo/metabolismo , Contagem de Células , Movimento Celular/efeitos dos fármacos , Células Cultivadas , Feminino , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Regulação da Expressão Gênica no Desenvolvimento/genética , Proteínas de Fluorescência Verde/genética , Humanos , Proteína Kangai-1/metabolismo , Oligodendroglia/metabolismo , RNA Interferente Pequeno/metabolismo , Ratos , Ratos Sprague-Dawley , Células-Tronco/classificaçãoRESUMO
Proneural gliomas are brain tumors characterized by enrichment of oligodendrocyte progenitor cell (OPC) transcripts and genetic alterations. In this study we sought to identify transcriptional and epigenetic differences between OPCs with Trp53 deletion and PDGF-BB overexpression (BB-p53n), which form tumors when transplanted in mouse brains, and those carrying only p53 deletion (p53n), which do not. We used unbiased histone proteomics and RNA-seq analysis on these two genetically modified OPC populations and detected higher levels of H3K27me3 in BB-p53n compared to p53n OPCs. The BB-p53n OPC were characterized by higher levels of transcripts related to proliferation and lower levels of those related to differentiation. Pharmacological inhibition of histone H3K27 trimethylation in BB-p53n OPC reduced cell cycle transcripts and increased the expression of differentiation markers. These data suggest that PDGF-BB overexpression in p53 null OPC results in histone post-translational modifications and consequent transcriptional changes favoring proliferation while halting differentiation, thereby promoting the early stages of transformation.
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Isocitrate Dehydrogenase-1 (IDH1) is commonly mutated in lower-grade diffuse gliomas. The IDH1R132H mutation is an important diagnostic tool for tumor diagnosis and prognosis; however, its role in glioma development, and its impact on response to therapy, is not fully understood. We developed a murine model of proneural IDH1R132H-mutated glioma that shows elevated production of 2-hydroxyglutarate (2-HG) and increased trimethylation of lysine residue K27 on histone H3 (H3K27me3) compared to IDH1 wild-type tumors. We found that using Tazemetostat to inhibit the methyltransferase for H3K27, Enhancer of Zeste 2 (EZH2), reduced H3K27me3 levels and increased acetylation on H3K27. We also found that, although the histone deacetylase inhibitor (HDACi) Panobinostat was less cytotoxic in IDH1R132H-mutated cells (either isolated from murine glioma or oligodendrocyte progenitor cells infected in vitro with a retrovirus expressing IDH1R132H) compared to IDH1-wild-type cells, combination treatment with Tazemetostat is synergistic in both mutant and wild-type models. These findings indicate a novel therapeutic strategy for IDH1-mutated gliomas that targets the specific epigenetic alteration in these tumors.
Assuntos
Compostos de Bifenilo , Glioma , Inibidores de Histona Desacetilases , Morfolinas , Piridonas , Animais , Camundongos , Inibidores de Histona Desacetilases/farmacologia , Inibidores de Histona Desacetilases/uso terapêutico , Histonas/genética , Glioma/tratamento farmacológico , Glioma/genética , Glioma/patologia , BenzamidasRESUMO
OBJECTIVE: Glioblastoma (GBM) is the most common and aggressive malignant primary brain tumor, and resection is a key part of the standard of care. In fluorescence-guided surgery (FGS), fluorophores differentiate tumor tissue from surrounding normal brain. The heme synthesis pathway converts 5-aminolevulinic acid (5-ALA), a fluorogenic substrate used for FGS, to fluorescent protoporphyrin IX (PpIX). The resulting fluorescence is believed to be specific to neoplastic glioma cells, but this specificity has not been examined at a single-cell level. The objective of this study was to determine the specificity with which 5-ALA labels the diversity of cell types in GBM. METHODS: The authors performed single-cell optical phenotyping and expression sequencing-version 2 (SCOPE-seq2), a paired single-cell imaging and RNA sequencing method, of individual cells on human GBM surgical specimens with macroscopically visible PpIX fluorescence from patients who received 5-ALA prior to surgery. SCOPE-seq2 allowed the authors to simultaneously image PpIX fluorescence and unambiguously identify neoplastic cells from single-cell RNA sequencing. Experiments were also conducted in cell culture and co-culture models of glioma and in acute slice cultures from a mouse glioma model to investigate cell- and tissue-specific uptake and secretion of 5-ALA and PpIX. RESULTS: SCOPE-seq2 analysis of human GBM surgical specimens revealed that 5-ALA treatment resulted in labeling that was not specific to neoplastic glioma cells. The cell culture further demonstrated that nonneoplastic cells could be labeled by 5-ALA directly or by PpIX secreted from surrounding neoplastic cells. Acute slice cultures from mouse glioma models showed that 5-ALA preferentially labeled GBM tumor tissue over nonneoplastic brain tissue with significant labeling in the tumor margins, and that this contrast was not due to blood-brain barrier disruption. CONCLUSIONS: Together, these findings support the use of 5-ALA as an indicator of GBM tissue but question the main advantage of 5-ALA for specific intracellular labeling of neoplastic glioma cells in FGS. Further studies are needed to systematically compare the performance of 5-ALA to that of potential alternatives for FGS.
Assuntos
Neoplasias Encefálicas , Glioblastoma , Glioma , Camundongos , Animais , Humanos , Ácido Aminolevulínico/metabolismo , Glioblastoma/diagnóstico por imagem , Glioblastoma/genética , Glioblastoma/cirurgia , Glioma/cirurgia , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/cirurgia , Fluorescência , Protoporfirinas , Análise de Célula Única , Fármacos FotossensibilizantesRESUMO
While efforts to identify microglial subtypes have recently accelerated, the relation of transcriptomically defined states to function has been largely limited to in silico annotations. Here, we characterize a set of pharmacological compounds that have been proposed to polarize human microglia towards two distinct states - one enriched for AD and MS genes and another characterized by increased expression of antigen presentation genes. Using different model systems including HMC3 cells, iPSC-derived microglia and cerebral organoids, we characterize the effect of these compounds in mimicking human microglial subtypes in vitro. We show that the Topoisomerase I inhibitor Camptothecin induces a CD74high/MHChigh microglial subtype which is specialized in amyloid beta phagocytosis. Camptothecin suppressed amyloid toxicity and restored microglia back to their homeostatic state in a zebrafish amyloid model. Our work provides avenues to recapitulate human microglial subtypes in vitro, enabling functional characterization and providing a foundation for modulating human microglia in vivo.
RESUMO
Gliomas are highly aggressive brain tumors characterized by poor prognosis and composed of diffusely infiltrating tumor cells that intermingle with non-neoplastic cells in the tumor microenvironment, including neurons. Neurons are increasingly appreciated as important reactive components of the glioma microenvironment, due to their role in causing hallmark glioma symptoms, such as cognitive deficits and seizures, as well as their potential ability to drive glioma progression. Separately, mTOR signaling has been shown to have pleiotropic effects in the brain tumor microenvironment, including regulation of neuronal hyperexcitability. However, the local cellular-level effects of mTOR inhibition on glioma-induced neuronal alterations are not well understood. Here we employed neuron-specific profiling of ribosome-bound mRNA via 'RiboTag,' morphometric analysis of dendritic spines, and in vivo calcium imaging, along with pharmacological mTOR inhibition to investigate the impact of glioma burden and mTOR inhibition on these neuronal alterations. The RiboTag analysis of tumor-associated excitatory neurons showed a downregulation of transcripts encoding excitatory and inhibitory postsynaptic proteins and dendritic spine development, and an upregulation of transcripts encoding cytoskeletal proteins involved in dendritic spine turnover. Light and electron microscopy of tumor-associated excitatory neurons demonstrated marked decreases in dendritic spine density. In vivo two-photon calcium imaging in tumor-associated excitatory neurons revealed progressive alterations in neuronal activity, both at the population and single-neuron level, throughout tumor growth. This in vivo calcium imaging also revealed altered stimulus-evoked somatic calcium events, with changes in event rate, size, and temporal alignment to stimulus, which was most pronounced in neurons with high-tumor burden. A single acute dose of AZD8055, a combined mTORC1/2 inhibitor, reversed the glioma-induced alterations on the excitatory neurons, including the alterations in ribosome-bound transcripts, dendritic spine density, and stimulus evoked responses seen by calcium imaging. These results point to mTOR-driven pathological plasticity in neurons at the infiltrative margin of glioma - manifested by alterations in ribosome-bound mRNA, dendritic spine density, and stimulus-evoked neuronal activity. Collectively, our work identifies the pathological changes that tumor-associated excitatory neurons experience as both hyperlocal and reversible under the influence of mTOR inhibition, providing a foundation for developing therapies targeting neuronal signaling in glioma.
RESUMO
Frontotemporal dementia (FTD) is an incurable group of early-onset dementias that can be caused by the deposition of hyperphosphorylated tau in patient brains. However, the mechanisms leading to neurodegeneration remain largely unknown. Here, we combined single-cell analyses of FTD patient brains with a stem cell culture and transplantation model of FTD. We identified disease phenotypes in FTD neurons carrying the MAPT-N279K mutation, which were related to oxidative stress, oxidative phosphorylation, and neuroinflammation with an upregulation of the inflammation-associated protein osteopontin (OPN). Human FTD neurons survived less and elicited an increased microglial response after transplantation into the mouse forebrain, which we further characterized by single nucleus RNA sequencing of microdissected grafts. Notably, downregulation of OPN in engrafted FTD neurons resulted in improved engraftment and reduced microglial infiltration, indicating an immune-modulatory role of OPN in patient neurons, which may represent a potential therapeutic target in FTD.
Assuntos
Demência Frontotemporal , Neurônios , Osteopontina , Proteínas tau , Osteopontina/metabolismo , Osteopontina/genética , Demência Frontotemporal/genética , Demência Frontotemporal/patologia , Demência Frontotemporal/metabolismo , Humanos , Neurônios/metabolismo , Neurônios/patologia , Animais , Proteínas tau/metabolismo , Camundongos , Doenças Neuroinflamatórias/metabolismo , Doenças Neuroinflamatórias/patologia , Microglia/metabolismo , Microglia/patologia , Mutação/genéticaRESUMO
Ferroptosis is mediated by lipid peroxidation of phospholipids containing polyunsaturated fatty acyl moieties. Glutathione, the key cellular antioxidant capable of inhibiting lipid peroxidation via the activity of the enzyme glutathione peroxidase 4 (GPX-4), is generated directly from the sulfur-containing amino acid cysteine, and indirectly from methionine via the transsulfuration pathway. Herein we show that cysteine and methionine deprivation (CMD) can synergize with the GPX4 inhibitor RSL3 to increase ferroptotic cell death and lipid peroxidation in both murine and human glioma cell lines and in ex vivo organotypic slice cultures. We also show that a cysteine-depleted, methionine-restricted diet can improve therapeutic response to RSL3 and prolong survival in a syngeneic orthotopic murine glioma model. Finally, this CMD diet leads to profound in vivo metabolomic, proteomic and lipidomic alterations, highlighting the potential for improving the efficacy of ferroptotic therapies in glioma treatment with a non-invasive dietary modification.
Assuntos
Ferroptose , Glioma , Humanos , Animais , Camundongos , Metionina , Cisteína , Proteômica , Racemetionina , Glioma/tratamento farmacológicoRESUMO
The epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) osimertinib has significantly prolonged progression-free survival (PFS) in patients with EGFR-mutant lung cancer, including those with brain metastases. However, despite striking initial responses, osimertinib-treated patients eventually develop lethal metastatic relapse, often to the brain. Although osimertinib-refractory brain relapse is a major clinical challenge, its underlying mechanisms remain poorly understood. Using metastatic models of EGFR-mutant lung cancer, we show that cancer cells expressing high intracellular S100A9 escape osimertinib and initiate brain relapses. Mechanistically, S100A9 upregulates ALDH1A1 expression and activates the retinoic acid (RA) signaling pathway in osimertinib-refractory cancer cells. We demonstrate that the genetic repression of S100A9, ALDH1A1, or RA receptors (RAR) in cancer cells, or treatment with a pan-RAR antagonist, dramatically reduces brain metastasis. Importantly, S100A9 expression in cancer cells correlates with poor PFS in osimertinib-treated patients. Our study, therefore, identifies a novel, therapeutically targetable S100A9-ALDH1A1-RA axis that drives brain relapse. SIGNIFICANCE: Treatment with the EGFR TKI osimertinib prolongs the survival of patients with EGFR-mutant lung cancer; however, patients develop metastatic relapses, often to the brain. We identified a novel intracellular S100A9-ALDH1A1-RA signaling pathway that drives lethal brain relapse and can be targeted by pan-RAR antagonists to prevent cancer progression and prolong patient survival. This article is highlighted in the In This Issue feature, p. 873.
Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Família Aldeído Desidrogenase 1 , Compostos de Anilina/farmacologia , Compostos de Anilina/uso terapêutico , Encéfalo/patologia , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Receptores ErbB/genética , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Mutação , Recidiva Local de Neoplasia/tratamento farmacológico , Recidiva Local de Neoplasia/genética , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Retinal Desidrogenase/genética , Transdução de Sinais , Tretinoína/farmacologiaRESUMO
Cortical interneurons establish inhibitory microcircuits throughout the neocortex and their dysfunction has been implicated in epilepsy and neuropsychiatric diseases. Developmentally, interneurons migrate from a distal progenitor domain in order to populate the neocortex - a process that occurs at a slower rate in humans than in mice. In this study, we sought to identify factors that regulate the rate of interneuron maturation across the two species. Using embryonic mouse development as a model system, we found that the process of initiating interneuron migration is regulated by blood vessels of the medial ganglionic eminence (MGE), an interneuron progenitor domain. We identified two endothelial cell-derived paracrine factors, SPARC and SerpinE1, that enhance interneuron migration in mouse MGE explants and organotypic cultures. Moreover, pre-treatment of human stem cell-derived interneurons (hSC-interneurons) with SPARC and SerpinE1 prior to transplantation into neonatal mouse cortex enhanced their migration and morphological elaboration in the host cortex. Further, SPARC and SerpinE1-treated hSC-interneurons also exhibited more mature electrophysiological characteristics compared to controls. Overall, our studies suggest a critical role for CNS vasculature in regulating interneuron developmental maturation in both mice and humans.
Assuntos
Movimento Celular/efeitos dos fármacos , Córtex Cerebral/metabolismo , Células-Tronco Pluripotentes Induzidas/efeitos dos fármacos , Interneurônios/efeitos dos fármacos , Eminência Mediana/irrigação sanguínea , Células-Tronco Neurais/efeitos dos fármacos , Neurogênese/efeitos dos fármacos , Osteonectina/farmacologia , Inibidor 1 de Ativador de Plasminogênio/farmacologia , Potenciais de Ação , Animais , Córtex Cerebral/embriologia , Córtex Cerebral/cirurgia , Células Endoteliais/metabolismo , Células HEK293 , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Células-Tronco Pluripotentes Induzidas/transplante , Interneurônios/metabolismo , Interneurônios/transplante , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Eminência Mediana/embriologia , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos da Linhagem 129 , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NOD , Camundongos Knockout , Neovascularização Fisiológica , Células-Tronco Neurais/metabolismo , Células-Tronco Neurais/transplante , Osteonectina/metabolismo , Comunicação Parácrina , Inibidor 1 de Ativador de Plasminogênio/metabolismo , Transdução de SinaisRESUMO
BACKGROUND: The development of non-small cell lung cancer (NSCLC) involves the progressive accumulation of genetic and epigenetic changes. These include somatic oncogenic KRAS and EGFR mutations and inactivating TP53 tumour suppressor mutations, leading to activation of canonical NF-κB. However, the mechanism(s) by which canonical NF-κB contributes to NSCLC is still under investigation. METHODS: Human NSCLC cells were used to knock-down RelA/p65 (RelA/p65KD) and investigate its impact on cell growth, and its mechanism of action by employing RNA-seq analysis, qPCR, immunoblotting, immunohistochemistry, immunofluorescence and functional assays. RESULTS: RelA/p65KD reduced the proliferation and tumour growth of human NSCLC cells grown in vivo as xenografts in immune-compromised mice. RNA-seq analysis identified canonical NF-κB targets mediating its tumour promoting function. RelA/p65KD resulted in the upregulation of the metastasis suppressor CD82/KAI1/TSPAN27 and downregulation of the proto-oncogene ROS1, and LGR6 involved in Wnt/ß-catenin signalling. Immunohistochemical and bioinformatics analysis of human NSCLC samples showed that CD82 loss correlated with malignancy. RelA/p65KD suppressed cell migration and epithelial-to-mesenchymal cell transition (EMT), mediated, in part, by CD82/KAI1, through integrin-mediated signalling involving the mitogenic ERK, Akt1 and Rac1 proteins. CONCLUSIONS: Canonical NF-κB signalling promotes NSCLC, in part, by downregulating the metastasis suppressor CD82/KAI1 which inhibits cell migration, EMT and tumour growth.
RESUMO
Aurora kinase A (AURKA) has emerged as a drug target for glioblastoma (GBM). However, resistance to therapy remains a critical issue. By integration of transcriptome, chromatin immunoprecipitation sequencing (CHIP-seq), Assay for Transposase-Accessible Chromatin sequencing (ATAC-seq), proteomic and metabolite screening followed by carbon tracing and extracellular flux analyses we show that genetic and pharmacological AURKA inhibition elicits metabolic reprogramming mediated by inhibition of MYC targets and concomitant activation of Peroxisome Proliferator Activated Receptor Alpha (PPARA) signaling. While glycolysis is suppressed by AURKA inhibition, we note an increase in the oxygen consumption rate fueled by enhanced fatty acid oxidation (FAO), which was accompanied by an increase of Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α). Combining AURKA inhibitors with inhibitors of FAO extends overall survival in orthotopic GBM PDX models. Taken together, these data suggest that simultaneous targeting of oxidative metabolism and AURKAi might be a potential novel therapy against recalcitrant malignancies.
Assuntos
Aurora Quinase A/genética , Aurora Quinase A/metabolismo , Glioblastoma/genética , Glioblastoma/metabolismo , Efeito Warburg em Oncologia , Linhagem Celular Tumoral , Proliferação de Células , Ácidos Graxos/metabolismo , Glicólise/efeitos dos fármacos , Humanos , PPAR alfa/metabolismo , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Proteômica , Transdução de Sinais/efeitos dos fármacos , Transcriptoma , Efeito Warburg em Oncologia/efeitos dos fármacosRESUMO
PURPOSE: Glioblastoma (GBM) is a devastating disease. With the current treatment of surgery followed by chemoradiation, outcomes remain poor, with median survival of only 15 months and a 5-year survival rate of 6.8%. A challenge in treating GBM is the heterogeneous integrity of the blood-brain barrier (BBB), which limits the bioavailability of systemic therapies to the brain. There is a growing interest in enhancing drug delivery by opening the BBB with the use of focused ultrasound (FUS). We hypothesize that an FUS-mediated BBB opening can enhance the delivery of etoposide for a therapeutic benefit in GBM. METHODS AND MATERIALS: A murine glioma cell line (Pdgf+, Pten-/-, P53-/-) was orthotopically injected into B6(Cg)-Tyrc-2J/J mice to establish the syngeneic GBM model for this study. Animals were treated with FUS and microbubbles to open the BBB to enhance the delivery of systemic etoposide. Magnetic resonance (MR) imaging was used to evaluate the BBB opening and tumor progression. Liquid chromatography tandem mass spectrometry was used to measure etoposide concentrations in the intracranial tumors. RESULTS: The murine glioma cell line is sensitive to etoposide in vitro. MR imaging and passive cavitation detection demonstrate the safe and successful BBB opening with FUS. The combined treatment of an FUS-mediated BBB opening and etoposide decreased tumor growth by 45% and prolonged median overall survival by 6 days: an approximately 30% increase. The FUS-mediated BBB opening increased the brain tumor-to-serum ratio of etoposide by 3.5-fold and increased the etoposide concentration in brain tumor tissue by 8-fold compared with treatment without ultrasound. CONCLUSIONS: The current study demonstrates that BBB opening with FUS increases intratumoral delivery of etoposide in the brain, resulting in local control and overall survival benefits.
Assuntos
Antineoplásicos Fitogênicos/administração & dosagem , Barreira Hematoencefálica/fisiologia , Neoplasias Encefálicas/tratamento farmacológico , Etoposídeo/administração & dosagem , Glioblastoma/tratamento farmacológico , Ultrassonografia de Intervenção/métodos , Animais , Antineoplásicos Fitogênicos/análise , Barreira Hematoencefálica/diagnóstico por imagem , Neoplasias Encefálicas/química , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/mortalidade , Linhagem Celular Tumoral , Cromatografia Líquida , Meios de Contraste/administração & dosagem , Progressão da Doença , Etoposídeo/análise , Glioblastoma/química , Glioblastoma/diagnóstico por imagem , Glioblastoma/mortalidade , Imageamento por Ressonância Magnética , Masculino , Camundongos , Microbolhas , Sonicação , Espectrometria de Massas em TandemRESUMO
In the adult mammalian brain, oligodendrocyte progenitors can differentiate into mature oligodendrocytes during remyelination. Mechanisms that regulate migration and differentiation of progenitors are of great importance in understanding normal development and demyelinating/remyelinating conditions. In a microarray analysis comparing adult and neonatal O4-positive (+) cells, we found that the tetraspanin KAI1/CD82 is far more highly expressed in adult O4(+) cells than in neonatal O4(+) cells (Lin et al., 2009). CD82 is a metastasis suppressor, and its expression is often downregulated or lost in the advanced stages of metastatic cancer. We hypothesized that CD82 could be a factor that restricts migration and promotes differentiation of maturing oligodendrocytes. Western blot analysis of isolated adult O4(+) cells confirms the elevated levels of CD82, which continues to be expressed as these become O1(+) in vitro. In the adult rat white matter, CD82 is coexpressed with CC1 and olig2 but not with NG2 or GFAP. Immature cells of the neonatal forebrain subventricular zone (SVZ) infected in vivo with a retrovirus that constitutively expresses CD82 do not remain immature but differentiate into either CC1(+) and MBP(+) myelinating oligodendrocytes in the white matter or zebrinII(+) astrocytes in the cortex. Their migration from the SVZ is severely restricted. In contrast, downregulation of CD82 in SVZ cells in vivo, using retroviral-expressed short hairpin RNAs (shRNAs), prevents their differentiation into myelinating oligodendrocytes. shRNA-expressing cells remained PDGF receptor alpha positive, olig2(+), or NG2(+) or became CC1(+) nonmyelinating oligodendrocytes or GFAP(+) astrocytes. CD82 thus appears to be a critical molecule in the regulation of oligodendrocyte progenitor migration and myelination.
Assuntos
Diferenciação Celular/genética , Movimento Celular/genética , Proteína Kangai-1/biossíntese , Bainha de Mielina/genética , Oligodendroglia/metabolismo , Células-Tronco/metabolismo , Animais , Animais Recém-Nascidos , Linhagem da Célula/genética , Células Cultivadas , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Proteína Kangai-1/genética , Proteína Kangai-1/fisiologia , Bainha de Mielina/fisiologia , Neurogênese/genética , Oligodendroglia/citologia , Ratos , Ratos Sprague-Dawley , Células-Tronco/citologiaRESUMO
The Warburg effect is a tumor-related phenomenon that could potentially be targeted therapeutically. Here, we showed that glioblastoma (GBM) cultures and patients' tumors harbored super-enhancers in several genes related to the Warburg effect. By conducting a transcriptome analysis followed by ChIP-Seq coupled with a comprehensive metabolite analysis in GBM models, we found that FDA-approved global (panobinostat, vorinostat) and selective (romidepsin) histone deacetylase (HDAC) inhibitors elicited metabolic reprogramming in concert with disruption of several Warburg effect-related super-enhancers. Extracellular flux and carbon-tracing analyses revealed that HDAC inhibitors blunted glycolysis in a c-Myc-dependent manner and lowered ATP levels. This resulted in the engagement of oxidative phosphorylation (OXPHOS) driven by elevated fatty acid oxidation (FAO), rendering GBM cells dependent on these pathways. Mechanistically, interference with HDAC1/-2 elicited a suppression of c-Myc protein levels and a concomitant increase in 2 transcriptional drivers of oxidative metabolism, PGC1α and PPARD, suggesting an inverse relationship. Rescue and ChIP experiments indicated that c-Myc bound to the promoter regions of PGC1α and PPARD to counteract their upregulation driven by HDAC1/-2 inhibition. Finally, we demonstrated that combination treatment with HDAC and FAO inhibitors extended animal survival in patient-derived xenograft model systems in vivo more potently than single treatments in the absence of toxicity.
Assuntos
Reprogramação Celular/efeitos dos fármacos , Glioblastoma , Glicólise/efeitos dos fármacos , Inibidores de Histona Desacetilases/farmacologia , Fosforilação Oxidativa/efeitos dos fármacos , Animais , Ácidos Graxos/metabolismo , Glioblastoma/tratamento farmacológico , Glioblastoma/metabolismo , Glioblastoma/patologia , Células HCT116 , Histona Desacetilase 1/antagonistas & inibidores , Histona Desacetilase 1/metabolismo , Histona Desacetilase 2/antagonistas & inibidores , Histona Desacetilase 2/metabolismo , Humanos , Camundongos , PPAR delta/metabolismo , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Proteínas Proto-Oncogênicas c-myc/metabolismo , Elementos de RespostaRESUMO
PURPOSE: Cancer immunoediting shapes tumor progression by the selection of tumor cell variants that can evade immune recognition. Given the immune evasion and intratumor heterogeneity characteristic of gliomas, we hypothesized that CD8+ T cells mediate immunoediting in these tumors. EXPERIMENTAL DESIGN: We developed retrovirus-induced PDGF+ Pten -/- murine gliomas and evaluated glioma progression and tumor immunogenicity in the absence of CD8+ T cells by depleting this immune cell population. Furthermore, we characterized the genomic alterations present in gliomas that developed in the presence and absence of CD8+ T cells. RESULTS: Upon transplantation, gliomas that developed in the absence of CD8+ T cells engrafted poorly in recipients with intact immunity but engrafted well in those with CD8+ T-cell depletion. In contrast, gliomas that developed under pressure from CD8+ T cells were able to fully engraft in both CD8+ T-cell-depleted mice and immunocompetent mice. Remarkably, gliomas developed in the absence of CD8+ T cells exhibited increased aneuploidy, MAPK pathway signaling, gene fusions, and macrophage/microglial infiltration, and showed a proinflammatory phenotype. MAPK activation correlated with macrophage/microglia recruitment in this model and in the human disease. CONCLUSIONS: Our studies indicate that, in these tumor models, CD8+ T cells influence glioma oncogenic pathways, tumor genotype, and immunogenicity. This suggests immunoediting of immunogenic tumor clones through their negative selection by CD8+ T cells during glioma formation.
Assuntos
Neoplasias Encefálicas/imunologia , Glioma/imunologia , Evasão da Resposta Imune/imunologia , Linfócitos T/imunologia , Animais , Antígenos de Neoplasias/imunologia , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Linfócitos T CD8-Positivos/imunologia , Modelos Animais de Doenças , Glioma/genética , Glioma/patologia , Humanos , Macrófagos/imunologia , Macrófagos/patologia , Camundongos , Microglia/imunologia , Microglia/patologia , Linfócitos T/patologiaRESUMO
Diffusely infiltrating gliomas are known to cause alterations in cortical function, vascular disruption, and seizures. These neurological complications present major clinical challenges, yet their underlying mechanisms and causal relationships to disease progression are poorly characterized. Here, we follow glioma progression in awake Thy1-GCaMP6f mice using in vivo wide-field optical mapping to monitor alterations in both neuronal activity and functional hemodynamics. The bilateral synchrony of spontaneous neuronal activity gradually decreases in glioma-infiltrated cortical regions, while neurovascular coupling becomes progressively disrupted compared to uninvolved cortex. Over time, mice develop diverse patterns of high amplitude discharges and eventually generalized seizures that appear to originate at the tumors' infiltrative margins. Interictal and seizure events exhibit positive neurovascular coupling in uninfiltrated cortex; however, glioma-infiltrated regions exhibit disrupted hemodynamic responses driving seizure-evoked hypoxia. These results reveal a landscape of complex physiological interactions occurring during glioma progression and present new opportunities for exploring novel biomarkers and therapeutic targets.
Assuntos
Glioma/fisiopatologia , Acoplamento Neurovascular/fisiologia , Animais , Encéfalo/fisiopatologia , Córtex Cerebral/metabolismo , Progressão da Doença , Hemodinâmica/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Rede Nervosa/fisiopatologia , Neurônios/metabolismo , Convulsões/fisiopatologiaRESUMO
The receptor kinase c-MET has emerged as a target for glioblastoma therapy. However, treatment resistance emerges inevitably. Here, we performed global metabolite screening with metabolite set enrichment coupled with transcriptome and gene set enrichment analysis and proteomic screening, and identified substantial reprogramming of tumor metabolism involving oxidative phosphorylation and fatty acid oxidation (FAO) with substantial accumulation of acyl-carnitines accompanied by an increase of PGC1α in response to genetic (shRNA and CRISPR/Cas9) and pharmacologic (crizotinib) inhibition of c-MET. Extracellular flux and carbon tracing analyses (U-13C-glucose, U-13C-glutamine, and U-13C-palmitic acid) demonstrated enhanced oxidative metabolism, which was driven by FAO and supported by increased anaplerosis of glucose carbons. These findings were observed in concert with increased number and fusion of mitochondria and production of reactive oxygen species. Genetic interference with PGC1α rescued this oxidative phenotype driven by c-MET inhibition. Silencing and chromatin immunoprecipitation experiments demonstrated that cAMP response elements binding protein regulates the expression of PGC1α in the context of c-MET inhibition. Interference with both oxidative phosphorylation (metformin, oligomycin) and ß-oxidation of fatty acids (etomoxir) enhanced the antitumor efficacy of c-MET inhibition. Synergistic cell death was observed with c-MET inhibition and gamitrinib treatment. In patient-derived xenograft models, combination treatments of crizotinib and etomoxir, and crizotinib and gamitrinib were significantly more efficacious than single treatments and did not induce toxicity. Collectively, we have unraveled the mechanistic underpinnings of c-MET inhibition and identified novel combination therapies that may enhance its therapeutic efficacy. SIGNIFICANCE: c-MET inhibition causes profound metabolic reprogramming that can be targeted by drug combination therapies.